Firearm action



W. J. NITTLER FIREARM ACTION Feb. 21, 1967 Filed June 25, 1965 INVENTOR. WILL/AM J. NITTLER ATTORNEYS United States Patent 3,304,643 Patented Feb. 21, 1967 3,304,643 FIREARM ACTION William J. Nittler, 2110 32nd Ave., San Francisco, Calif. 94116 Filed June 23, 1965, Ser. No. 466,324 3 Claims. (Cl. 42-42) This invention relates to firearm actions and more particularly to an improved action for double barrelled shotguns and the like.

It is an object of this invention to provide an improved action for double barrelled shotguns and the like which is very durable and reliable and which will provide a minimum ignition time, that is, a minimum time lapse between trigger motion and the striking of a firing pin by a hammer.

It is another object of the invention to provide such an improved action which is very compact and occupies a minimum space in the receiver of a firearm.

It is another object of the invention to provide such an improved action which has substantially the same structure and ignition time for both barrels of a double barrel firearm and which provides substantially the same striking power on both firing pins of the weapon.

Other objects and advantages of the invention will become apparent from the following description, read in conjunction with the attached drawings, in which:

FIG. 1 is a view in side elevation of a firearm action embodying the principles of this invention with a portion of the receiver side wall of the firearm broken away;

FIG. 2 is a top view of the action of FIG. 1 taken along the plane and in the direction indicated by the line and the arrows at 22 in FIG. 1 with the top wall of the receiver broken away;

FIG. 3 is a sectional view of the action of FIGS. 1 and 2 taken along the plane and in the direction indicated at 3-3 in FIG. 2;

FIG. 4 is a sectional view of the action of FIGS. l-3 taken along the plane and in the direction indicated at 4-4 in FIG. 3, and

FIG. 5 is a perspective view of the hammer and spring components illustrated in FIG. 1.

Broadly stated, this invention relates to a firearm having a barrel, a receiver mounted at the rearward end of the barrel and having a forward receiver wall which closes the rearward end of the barrel, a firing pin extending through said forward receiver wall, and a trigger, and the invention is the improvement comprising a hammer pivotally mounted in the receiver at an axis laterally spaced from and generally perpendicular to the firing pin, a coiled compression spring mounted under compression between the hammer and a wall of the receiver with the spring having a central axis positioned between the forward receiver wall and the hammer axis generally perpendicular to both the firing pin and hammer axis, and a firing train including a scar interconnecting the hammer and the trigger. For the purposes of illustration herein, the invention is illustrated as a modification of a model 800 superposed shotgun manufactured by the B. C. Miroku Firearms Company, Kochi, Japan.

Referring now in detail to the attached drawings, the firearm illustrated therein includes a pair of superposed barrels and 12 pivotally mounted on a receiver 14 at a pivot axis 16. The receiver 14 is provided with a forward receiver wall 18 which closes the rearward end of the barrels 10 and 12.

A pair of firing pins 20 and 22 extend through the forward receiver wall 18 into the barrels 10 and 12 respectively coaxially thereof for discharging center-fire cartridges therein. A single trigger 24 is pivotally mounted in the receiver 14 and is connected by a connector 26, and

inertia block 28 and a pair of sears 30 and 32 to a pair of hammers 34 and 36 respectively which are arranged to strike the firing pins 20 and 22 respectively.

The hammers 34 and 36 are pivotally mounted to wall portions of the receiver 14 at pivotal axes 38 and 40 respectively so that both of the hammers swing to strike a firing pin on the side of the receiver opposite to the side at which the hammer is pivotally mounted. As indicated in FIGS. 2 and 4, the two hammers 34 and 36 are mounted on opposite sides of a center plane of the receiver through the two firing pins, and as indicated in FIG. 5, each of the hammers (here the hammer 36) is provided with lateral extension 42 which projects into the center plane of the receiver to strike the firing pin when the hammer is released by motion of the sear. As also indicated in FIG. 5, each of the hammers is provided with a sear notch 44 and a projecting ear 46 provided with a frustospherical seat 48.

The spring drive for each of the hammers 34 and 36 i provided by a coiled compression spring 50 and 52 respectively which are mounted on spring guides 54 and 56. The spring guides are provided with a spring supporting flange 58 and a frusto-spherical end portion 60 which is received in the frusto-spherical seat 48 in the hammer. The springs 50 and 52 extend generally perpendicular to both the firing pins 20 and 22 and the hammer axes 3S and 40 between the hammer axes 38 and 40 and the forward wall 18 of the receiver.

The hammers 34 and 36 are cocked by a conventional cocking arm 62 which is pivotally mounted in the receiver on a pivot pin 64, and a cocking arm lifter 66 is mounted in the lower edge of the barrels for rocking the cocking arm 62 when the breach of the shotgun is opened. A conventional top lever 68 is connected by a shaft 70 and a lateral lever 72 to a locking bolt 74 which locks the barrels in firing position. A coiled compression spring 76 engages the locking bolt 72 to urge the locking bolt into its locking position. Additionally, a conventional selector and safety lever 72; is mounted on top of the receiver for manipulating the inertia block 28 for interrupting the firing train and selecting which of the two barrels 10 and 12 will be fired first.

While one specific embodiment of the invention has been illustrated and described in detail herein, it is obvious that many modification thereof may be made without departing from the spirit and scope of the invention.

I claim:

1. In a firearm having a barrel, a receiver mounted at the rearward end of the barrel and having a forward receiver wall which closes the rearward end of the barrel, a firing pin extending through said forward receiver Wall with said firing pin lying in a plane, and a trigger, the improvement comprising a hammer laterally spaced from said plane and pivotally mounted in said receiver at an axis which is laterally spaced from said firing pin and generally perpendicular to said plane, a coiled compres sion spring mounted under compression between said hammer and a wall of said receiver with said spring having a central axis extending past said hammer and positioned between said forward receiver wall and said hamnier axis generally parallel to said plane, an extension on said hammer extending from said hammer laterally through said plane and forwardly toward said firing pin with the forwardly extending; dimension of said extension exceeding the diameter of said spring whereby engagement of said extension with said firing pin prevents said hammer from striking said spring, means for cocking said hammer, and firing means including a sear interconnecting said hammer and said trigger.

2. The improvement of claim 1 characterized further by the inclusion of a spring guide mounted on said spring coaxially thereof and having a frusto-spherical end thereon, and a frusto-spherical seat on said hammer engaging said spring guide.

3. In a double barrel firearm having first and second parallel barrels mounted together, a receiver mounted at the rearward end of said barrels and having a forward receiver wall which closes the rearward ends of said barrels, and first and second vertically spaced spaced apart firing pins extending through said forward receiver wall into said first and second barrels respectively, the improvement comprising a first hammer pivotally mounted in said receiver at an axis adjacent to said second firing pin and generally perpendicular to the vertical plane passing through said firing pins with said first hammer swingable upwardly counterclockwise to a position striking said first firing pin, a second hammer pivotally mounted in said receiver at an axis adjacent to said first firing pin and generally perpendicular to the vertical plane passing through said firing pins with said second hammer swingable downwardly clockwise to a position striking said second firing pin, two coiled compression springs, one mounted between one of said hammers and a wall of said receiver and the other spring mounted between the other hammer and a wall of said receiver, with each of said springs extending past the pivot axis of the other hammer and having a central axis positioned between said rearward ends of said barrels and the axes of said hammers generally perpendicular to the horizontal planes passing through both of said firing pins and both of said axes, cocking means for cocking said hammers, and firing means including two sears, the first sear connected to the first hammer and the second sear connected to the second hammer for releasing said hammers.

References Cited by the Examiner UNITED STATES PATENTS 980,174 12/1910 Flues 4242 1,302,909 5/1919 Giddings 42-42 X 1,792,732 2/1931 Crawford 424l BENJAMIN A BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Assistant Examiner. 

1. IN A FIREARM HAVING A BARREL, A RECEIVER MOUNTED AT THE REARWARD END OF THE BARREL AND HAVING A FORWARD RECEIVER WALL WHICH CLOSES THE REARWARD END OF THE BARREL, A FIRING PIN EXTENDING THROUGH SAID FORWARD RECEIVER WALL WITH SAID FIRING PIN LYING IN A PLANE, AND A TRIGGER, THE IMPROVEMENT COMPRISING A HAMMER LATERALLY SPACED FROM SAID PLANE AND PIVOTALLY MOUNTED IN SAID RECEIVER AT AN AXIS WHICH IS LAGERALLY SPACED FROM SAID FIRING PIN AND GENERALLY PERPENDICULAR TO SAID PLANE, A COILED COMPRESSION SPRING MOUNTED UNDER COMPRESSION BETWEEN SAID HAMMER AND A WALL OF SAID RECEIVER WITH SAID SPRING HAVING A CENTRAL AXIS EXTENDING PAST SAID HAMMER AND POSITIONED BETWEEN SAID FORWARD RECEIVER WALL AND SAID HAMMER AXIS GENERALLY PARALLEL TO SAID PLANE, AN EXTENSION ON SAID HAMMER EXTENDING FROM SAID HAMMER LATERALLY THROUGH SAID PLANE AND FORWARDLY TOWARD SAID FIRING PIN WITH THE FORWARDLY EXTENDING DIMENSION OF SAID EXTENSION EXCEEDING THE DIAMETER OF SAID SPRING WHEREBY ENGAGEMENT OF SAID EXTENSION WITH SAID FIRING PIN PREVENTS SAID HAMMER FROM STRIKING SAID SPRING, MEANS FOR COCKING SAID HAMMER, AND FIRING MEANS INCLUDING A SEAR INTERCONNECTING SAID HAMMER AND SAID TRIGGER. 